1. Field of the Invention
The present invention relates to an SECo.sub.5 permanent magnet joined to at least one iron mass and a method of fabricating such a permanent magnet.
2. Description of the Prior Art
SECo.sub.5 -permanent magnets, wherein SE donotes at least one of the elements in the atomic number range 58-71 of the Periodic Table have become very important in the manufacture of motors, magnetic bearings and clutches as well as in the construction of traveling-wave tubes because of their exceptionally high coercive force and remanence. In all these applications, the permanent magnets must be joined to iron alloys. In DT-PS No. 852,585, for example, a permanent magnet with a soft-iron layer sintered onto it is disclosed. However, such a device can only be made at temperatures above those which SECo.sub.5 -permanent magnets can endure. Attempts by the applicant to join the SECo.sub.5 permanent magnet to an iron mass by soft-soldering did not prove successful since the chemically active fluxes used in soft-soldering react with the magnet material and greatly reduce both the strength of the bond and the magnetic properties of the permanent magnet after soldering. Cementing of the permanent magnet to the iron mass was also tried by the applicant, but is not particularly advantageous, since a part fabricated in this manner can be heated at most to only 100.degree.-200.degree. C. without harmful effects on its mechanical strength. Soldered SECo.sub.5 -permanent magnets with high mechanical strength are disclosed in DT-OS No. 2,340,018, but they are made by a method applicable exclusively to joining similar magnetic materials.